Cutting elements, methods for manufacturing such cutting elements, and tools incorporating such cutting elements

Abstract

The present disclosure relates to cutting elements incorporating polycrystalline diamond bodies used for subterranean drilling applications, and more particularly, to polycrystalline diamond bodies having a high diamond content which are configured to provide improved properties of thermal stability and wear resistance, while maintaining a desired degree of impact resistance, when compared to prior polycrystalline diamond bodies. In various embodiments disclosed herein, a cutting element with high diamond content includes a modified PCD structure and/or a modified interface (between the PCD body and a substrate), to provide superior performance.

What is claimed is: 
     
       1. A cutting element comprising:
 a polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond grains and interstitial regions between the diamond grains; 
 
 wherein a first region of the microstructure proximate the cutting edge comprises a plurality of the interstitial regions that are substantially free of a catalyst material, and wherein the first region extends from the cutting edge to a depth of at least 300 microns, 
 wherein a second region of the microstructure proximate the interface surface comprises a plurality of the interstitial regions comprising the catalyst material disposed therewithin, 
 wherein the first region comprises a diamond average grain size less than 25 microns, and 
 wherein the first region has at least one of the following properties:
 an apparent porosity less than (0.1051)·(the diamond average grain size ^−0.3737), or 
 a leached weight loss less than (0.251)·(the diamond average grain size ^−0.2691), or 
 a diamond volume fraction greater than (0.9077)·(the diamond average grain size ^0.0221), 
 
 with the diamond average grain size provided in microns. 
 
     
     
       2. The cutting element of  claim 1 , wherein the apparent porosity in the first region is less than (0.1051)·(the average grain size ^−0.3737). 
     
     
       3. The cutting element of  claim 1 , wherein the leached weight loss in the first region is less than (0.251)·(the average grain size ^−0.2691). 
     
     
       4. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than (0.9077)·(the average grain size ^ 0.0221). 
     
     
       5. The cutting element of  claim 1 , wherein the polycrystalline diamond body requires at least 3 days at a standard leaching condition to form the first region. 
     
     
       6. The cutting element of  claim 1 , wherein the polycrystalline diamond body requires at least 4 days at a standard leaching condition to form the first region. 
     
     
       7. The cutting element of  claim 1 , wherein the polycrystalline diamond body requires at least 8 days at a standard leaching condition to form the first region. 
     
     
       8. The cutting element of  claim 1 , wherein the first region extends from the cutting edge to a depth of at least 400 microns. 
     
     
       9. The cutting element of  claim 1 , wherein the first region extends from the cutting edge to a depth of at least 500 microns. 
     
     
       10. The cutting element of  claim 1 , wherein the first region has at least one of the following properties:
 the apparent porosity is less than (0.091)·(the average grain size ^−0.3471), or 
 the leached weight loss is less than (0.2328)·(the average grain size ^−0.2653), or 
 the diamond volume fraction is greater than (0.9187)·(the average grain size ^ 0.0183). 
 
     
     
       11. The cutting element of  claim 1 , wherein the first region has at least one of the following properties:
 the apparent porosity is less than (0.0744)·(the average grain size ^−0.2932), or 
 the leached weight loss is less than (0.2052)·(the average grain size ^−0.2455), or 
 the diamond volume fraction is greater than (0.9291)·(the average grain size ^ 0.0148). 
 
     
     
       12. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than 91% and the average grain size in the first region is less than 3 microns. 
     
     
       13. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than 93% and the average grain size in the first region is less than 8 microns. 
     
     
       14. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than 94% and the average grain size in the first region is less than 13 microns. 
     
     
       15. The cutting element of  claim 1 , wherein the second region comprises a diamond volume fraction that is less than the diamond volume fraction of the first region. 
     
     
       16. The cutting element of  claim 1 , wherein the first region extends along an entire perimeter of the cutting element. 
     
     
       17. The cutting element of  claim 1 , wherein the first region extends along a portion of the top surface of the polycrystalline diamond body. 
     
     
       18. The cutting element of  claim 1 , wherein the first region extends along at least a critical zone of the polycrystalline diamond body. 
     
     
       19. The cutting element of  claim 1 , wherein the first region extends along the entire top surface, the cutting edge, and at least a portion of a side surface. 
     
     
       20. The cutting element of  claim 19 , wherein the depth of the first region along the top surface, the cutting edge, and the side surface extends to at least 300 microns within the diamond body. 
     
     
       21. The cutting element of  claim 1 , wherein the second region comprises a larger average grain size than that of the first region. 
     
     
       22. The cutting element of  claim 1 , wherein the interstitial regions in the second region have a larger size than those in the first region. 
     
     
       23. The cutting element of  claim 1 , further comprising a substrate bonded to the second region, and an interface between the substrate and the second region. 
     
     
       24. The cutting element of  claim 23 , wherein the substrate comprises a cobalt content within the range of approximately 6 to 11% by weight. 
     
     
       25. The cutting element of  claim 23 , wherein the interface comprises a dome having a height to diameter ratio of less than approximately 0.1. 
     
     
       26. The cutting element of  claim 23 , wherein the interface comprises a protrusion having a protrusion ratio between 0.5 and 1.0. 
     
     
       27. The cutting element of  claim 23 , wherein the interface comprises a protrusion having a protrusion ratio less than 0.4. 
     
     
       28. The cutting element of  claim 23 , wherein the interface comprises a smooth surface devoid of protrusions and depressions. 
     
     
       29. The cutting element of  claim 1 , wherein the polycrystalline diamond body further comprises a third region between the first and second regions, the third region having a lower catalyst content than that of the second region. 
     
     
       30. The cutting element of  claim 1 , wherein a property of the material microstructure varies along a gradient within the diamond body. 
     
     
       31. The cutting element of  claim 1 , wherein the polycrystalline diamond body has a dry vertical turret lathe (VTL) cutting distance of at least 5500 feet prior to formation of the first region having the interstitial regions that are substantially free of the catalyst material. 
     
     
       32. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 1  disposed thereon. 
     
     
       33. The downhole tool of  claim 32 , wherein the downhole tool comprises a drill bit. 
     
     
       34. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than (0.9187)·(the average grain size ^ 0.0183). 
     
     
       35. The cutting element of  claim 1 , wherein the diamond volume fraction in the first region is greater than (0.9291)·(the average grain size ^ 0.0148). 
     
     
       36. The cutting element of  claim 1 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       37. A cutting element comprising:
 a polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond grains and interstitial regions between the diamond grains; 
 
 wherein a first layer of the microstructure proximate the cutting edge comprises a first diamond volume fraction, 
 wherein a second layer of the microstructure proximate the interface surface comprises a second diamond volume fraction that is at least approximately 2% less than the first diamond volume fraction, and 
 wherein the first layer has at least one of the following properties:
 an apparent porosity less than (0.1051)·(the diamond average grain size ^ 0.3737), or 
 a leached weight loss less than (0.251)·(the diamond average grain size ^ 0.2691), or 
 the first diamond volume fraction is greater than (0.9077)·(the diamond average grain size ^ 0.0221), 
 
 with the diamond average grain size provided in microns. 
 
     
     
       38. The cutting element of  claim 37 , wherein the first layer comprises an average grain size less than 25 microns. 
     
     
       39. The cutting element of  claim 37 , wherein the first layer has a first grain size distribution and the second layer has a second grain size distribution which is different from the first grain size distribution of the first layer. 
     
     
       40. The cutting element of  claim 37 , wherein a first region of the polycrystalline diamond body extending from the cutting edge comprises a plurality of the interstitial regions that are substantially free of a catalyst material, and wherein a second region proximate the interface comprises a plurality of the interstitial regions comprising the catalyst material disposed therewithin. 
     
     
       41. The cutting element of  claim 40 , wherein the first region extends partially through the first layer. 
     
     
       42. The cutting element of  claim 40 , wherein at least a portion of the first region extends through the first layer and into the second layer. 
     
     
       43. The cutting element of  claim 40 , wherein the first region extends to a depth of no more than 100 microns. 
     
     
       44. The cutting element of  claim 40 , wherein the first region extends to a depth within a range of 100 to less than 300 microns. 
     
     
       45. The cutting element of  claim 40 , wherein the first region extends to a depth of at least 300 microns. 
     
     
       46. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 37  disposed thereon. 
     
     
       47. The cutting element of  claim 37 , wherein the diamond volume fraction in the first region is greater than (0.9187)·(the average grain size ^ 0.0183). 
     
     
       48. The cutting element of  claim 37 , wherein the diamond volume fraction in the first region is greater than (0.9291)·(the average grain size ^ 0.0148). 
     
     
       49. The cutting element of  claim 37 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       50. A cutting element comprising:
 a polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond grains and interstitial regions between the diamond grains; 
 
 wherein a first region of the microstructure proximate the cutting edge comprises a plurality of the interstitial regions that are substantially free of a catalyst material, 
 wherein the interface surface comprises a protrusion ratio of less than 0.7, 
 wherein the first region comprises a diamond average grain size less than 25 microns, and 
 wherein the first region has at least one of the following properties:
 an apparent porosity less than (0.1051)·(the diamond average grain size ^ 0.3737), or 
 a leached weight loss less than (0.251)·(the diamond average grain size ^ 0.2691), or 
 a diamond volume fraction greater than (0.9077)·(the diamond average grain size ^0.0221), 
 
 with the diamond average grain size provided in microns. 
 
     
     
       51. The cutting element of  claim 50 , wherein the first region extends to a depth of no more than 100 microns. 
     
     
       52. The cutting element of  claim 50 , wherein the first region extends to a depth within a range of 100 to less than 300 microns. 
     
     
       53. The cutting element of  claim 50 , wherein the first region extends to a depth of at least 300 microns. 
     
     
       54. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 50  disposed thereon. 
     
     
       55. The cutting element of  claim 50 , wherein the diamond volume fraction in the first region is greater than (0.9187)·(the average grain size ^ 0.0183). 
     
     
       56. The cutting element of  claim 50 , wherein the diamond volume fraction in the first region is greater than (0.9291)·(the average grain size ^ 0.0148). 
     
     
       57. The cutting element of  claim 50 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       58. A cutting element comprising:
 a substrate having an interface surface, wherein the substrate comprises a cobalt content less than approximately 11% by weight; and 
 a polycrystalline diamond body formed over the interface surface of the substrate, the polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond grains and interstitial regions between the diamond grains, and 
 
 wherein a portion of the polycrystalline diamond body has at least one of the following properties:
 an apparent porosity less than (0.1051)·(the diamond average grain size ^−0.3737), or 
 a leached weight loss less than (0.251)·(the diamond average grain size ^ 0.2691), or 
 a diamond volume fraction greater than (0.9077)·(the diamond average grain size ^ 0.0221), 
 
 with the diamond average grain size provided in microns. 
 
     
     
       59. The cutting element of  claim 58 , wherein at least a portion of the polycrystalline diamond body comprises a an average grain size less than 25 microns. 
     
     
       60. The cutting element of  claim 58 , wherein the substrate comprises a cobalt content within the range of approximately 9 to 11% by weight. 
     
     
       61. The cutting element of  claim 58 , wherein the material microstructure comprises a first region extending from the cutting edge and comprising a plurality of the interstitial regions that are substantially free of a catalyst material, and comprises a second region proximate the interface surface comprising a plurality of the interstitial regions comprising the catalyst material disposed therewithin. 
     
     
       62. The cutting element of  claim 61 , wherein the first region extends to a depth of no more than 100 microns. 
     
     
       63. The cutting element of  claim 61 , wherein the first region extends to a depth within a range of 100 to less than 300 microns. 
     
     
       64. The cutting element of  claim 61 , wherein the first region extends to a depth of at least 300 microns. 
     
     
       65. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 58  disposed thereon. 
     
     
       66. The cutting element of  claim 58 , wherein the diamond volume fraction in the first region is greater than (0.9187)·(the average grain size ^ 0.0183). 
     
     
       67. The cutting element of  claim 58 , wherein the diamond volume fraction in the first region is greater than (0.9291)·(the average grain size ^ 0.0148). 
     
     
       68. The cutting element of  claim 58 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       69. A cutting element comprising:
 a polycrystalline diamond body sintered at a sintering cold cell pressure greater than 5.4 GPa, the polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond grains and interstitial regions between the diamond grains; 
 
 wherein a first region of the microstructure proximate the cutting edge comprises a plurality of the interstitial regions that are substantially free of a catalyst material, and wherein the first region extends from the cutting edge to a depth of at least 300 microns, 
 wherein a second region of the microstructure proximate the interface surface comprises a plurality of the interstitial regions comprising the catalyst material disposed therewithin, 
 wherein the first region comprises a diamond average grain size less than 25 microns, and 
 wherein the first region comprises a diamond volume fraction greater than 92%. 
 
     
     
       70. The cutting element of  claim 69 , wherein the first region comprises an average grain size of at most 15 microns and a diamond volume fraction greater than 92.5%. 
     
     
       71. The cutting element of  claim 69 , wherein the first region comprises an average grain size in the range of from 2.5 to 12 microns and a diamond volume fraction greater than 92.5%. 
     
     
       72. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 69  disposed thereon. 
     
     
       73. The cutting element of  claim 69 , wherein the diamond volume fraction in the first region is greater than 95%. 
     
     
       74. The cutting element of  claim 73 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       75. The cutting element of  claim 69 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       76. A cutting element comprising:
 a polycrystalline diamond body comprising:
 an interface surface; 
 a top surface opposite the interface surface; 
 a cutting edge meeting the top surface; and 
 a material microstructure comprising a plurality of bonded-together diamond crystals and interstitial regions between the diamond crystals; 
 
 wherein a first region of the microstructure proximate the cutting edge comprises a plurality of the interstitial regions that are substantially free of a catalyst material, and wherein the first region extends from the cutting edge to a depth of at least 300 microns, 
 wherein a second region of the microstructure proximate the interface surface comprises a plurality of the interstitial regions comprising the catalyst material disposed therewithin, and 
 wherein the first region satisfies one of the following conditions:
 an average grain size within the range of 2-4 microns, and a diamond volume fraction greater than 93%, or 
 an average grain size within the range of 4-6 microns, and a diamond volume fraction greater than 94%, or 
 an average grain size within the range of 6-8 microns, and a diamond volume fraction greater than 95%, or 
 an average grain size within the range of 8-10 microns, and a diamond volume fraction greater than 95.5%, or 
 an average grain size within the range of 10-12 microns, and a diamond volume fraction greater than 96%. 
 
 
     
     
       77. A downhole tool comprising a tool body and at least one cutting element as claimed in  claim 76  disposed thereon. 
     
     
       78. The cutting element of  claim 76 , wherein the diamond volume fraction in the first region is greater than 95%. 
     
     
       79. The cutting element of  claim 78 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa. 
     
     
       80. The cutting element of  claim 76 , wherein the polycrystalline diamond body is formed by sintering at a cold cell pressure greater than 6.5 GPa.